Comparison of glycerol treatment in frog skeletal muscle and mammalian heart. An electrophysiological and morphological study.
Frog skeletal muscle and mammalian heart muscle were studied in vitro before and after glycerol treatment. Loss of contractility, changes in the action potential and disruption of the T system were observed in skeletal muscle cells. In mammalian heart muscle the T system was not disrupted with hypertonic glycerol treatment, and no significant electrophysiological changes were observed. The continuity between the T system and the extracellular space was investigated by diffusion tracer methods. Decrease of contractility during the hypertonic phase in the glycerol treatment was found to depend on tonicity. The results of this study clearly show that not only are there differences in morphology between skeletal and cardiac muscle, but there are also differences in the resistance to osmotic changes.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001001:Anura; D002417:Cattle; D002467:Cell Nucleus / Q000032:analysis; D002843:Chromatin / Q000032:analysis; D004058:Diffusion; D005110:Extracellular Space; D005990:Glycerol / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects*; D006352:Heart Ventricles; D006651:Histocytochemistry; D006982:Hypertonic Solutions; D008564:Membrane Potentials / Q000187:drug effects*; D008854:Microscopy, Electron; D009119:Muscle Contraction / Q000187:drug effects*; D009132:Muscles / Q000032:analysis / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D009206:Myocardium / Q000032:analysis / Q000166:cytology; D010544:Peroxidases / Q000032:analysis; D011896:Rana temporaria; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000502:physiology; D012756:Sheep; D013997:Time Factors
D002843:Chromatin; D006982:Hypertonic Solutions; D010544:Peroxidases; D005990:Glycerol